Silt deposition occurs in river beds and subsoil areas (D). Silt particles are fine enough to be carried by water and settle in areas where water flow slows down, such as river beds, floodplains, and subsoil layers. Grasslands (A) are surface vegetation areas, bedrock (B) is the solid rock beneath soil, and the C-Horizon (C) is the weathered rock layer below subsoil but not the primary deposition site.